<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>函数的组成</title>
  </head>
  <body>
    
    <script>
      var a = 5,
        b = 6;
      function sum() {
        return a + b;
      }
      var result = sum();
      console.log(result); //11
    </script>
  </body>
</html>
